How is an update processed ? n Classical mirroring systems : rdist, ftp, … – A master server contact each mirror one by one – Drawbacks : the more numerous the mirrors the more decreased the perf. of the overall system n Reliable Multicast technology – Advantage : not affected by the number of mirrors – Drawbacks : no standard available but products 25/05/98 Stéphane Boyera, Luc Ottavj 6

Hardware n On the Master Site (Sophia) – One master server housing files and being both multicast sources and unicast server – One Internet Multicast Router – One Satellite Router (Uplink) n On Mirror Sites – One Multicast router for both Internet and Satellite multicast groups – One server receiving the update by the three ways 25/05/98 Stéphane Boyera, Luc Ottavj 9